The final question in Monday’s night’s Republican presidential candidate debate was “What have you learned in the last two hours?”

The answer: Not nearly enough.

We heard sound bites on the economy: “This economy is stalled. It’s like a train on the tracks with no engine. And the administration has simply been putting all of this money in the caboose,” Herman Cain said.

We heard sound bites on the budget: “I think we need a president who’s optimistic, who has a pro-growth agenda,” Rick Santorum said.

And we heard that Tim Pawlenty prefers Coke over Pepsi, Ron Paul likes his Blackberry over an iPhone, and nobody likes taxes or President Barack Obama.

More often than not, CNN moderator John King opted to keep on truckin’ rather than insist on answers. Michele Bachmann, for example, was asked what she would say to Americans who don’t trust Wall Street without regulation. Bachmann promised to explain why she sponsored the repeal of the Dodd-Frank bill, but instead announced that she’s filed her paperwork to run for president. King welcomed her to the race, and Wall Street was forgotten.

It’s not entirely the debate sponsors’ fault. Any debate with more than three candidates is by definition a high-wire act. The desire to squeeze in at least one question on all the major issues leads to a severe time crunch. There’s little time for the candidates to interact, respond to each other’s positions or give voters much beyond bumper-sticker positions.

Even so, the real value of a debate is for voters to see where candidates differ on issues and philosophy and ideally have some basis to judge which is best. In Monday’s debate, there were only two such opportunities. The first was when a few candidates were asked whether Pawlenty’s goal of 5 percent economic growth was realistic. Nobody said it wasn’t, but the former Minnesota governor never quite explained how it was possible.

The second came when Mitt Romney was called on to defend the Massachusetts health-care plan. He gave his prepared answer, and no one felt inclined to challenge it. Not even Pawlenty, who had earlier coined the term ObamneyCare to liken Romney’s program to the federal plan that Republicans loathe.

One of the few questions where each candidate had to answer was on banning same-sex marriage. Four would favor a constitutional amendment. Bachmann was one of them, but she also said she wouldn’t interfere with state issues. Nobody asked how that was possible. Cain would let states decide, while Paul thinks the government should stay out if it.

I’d like to see a whole debate focused just on health care and another one on the economy. One that forces the candidates to really compare their ideas and defend their records, not just give speeches while standing next to each other.

We in the media crown debate-winners and label the losers. I wrote that Bachmann stood out on Monday, and poll-leader Romney emerged unscathed. Pawlenty and Cain had poorer showings in this debate than in the May outing in South Carolina. But that shouldn’t disqualify anyone.

Here in Iowa, we don’t have to rely on debates to choose candidates. We can meet them in person, ask our own questions and politely insist on actual answers. Then we can compare what we heard to what the other candidates have said.

If what you really care about is “thin crust or deep dish,” go ahead and ask, but be sure to follow up with “Why?” Maybe you’ll actually learn something interesting.